Several wells and springs near active faults in southern California have been monitored for the concentration of Rn, Na+, K+, Mg+2, and Cl- for periods of up to 24 months in an effort to see if any of these constituents show variations which may be related to seismic activity or environmental phenomena. A few of these sites have shown significant fluctuations. One site in the San Gabriel Mountains has shown relatively high radon in the summer and low radon in the winter, apparently following the annual precipitation cycle. However, this site showed no corresponding change in its chemistry. A second site near Wrightwood, California has shown an annual cycle in its chemical composition, but shows no change in radon. Ten days prior to the Big Bear earthquake (M~4.9), 70 km to the east, one sample from this site showed a 50% increase in radon, but no change in chemistry. A third site, 20 km north of the Malibu earthquake (M~5.0) showed radon variation ranging from 0.4 to 4 times the normal concentration for two months preceding and two months following the event. The chemistry at this site did not change. Within this study area, radon appears to exhibit anomalous variations within several tens of kilometers of impending earthquakes. The mechanism creating these signals has not been elucidated, but does not influence the composition of important ionic constituents. Groundwater radon concentrations may also reflect variations in precipitation but do not appear to reflect variations in atmospheric pressure. Data from cold springs are consistent with a model in which ionic constituents are controlled by reactions in the soil zone and radon concentrations are controlled by flow rates in the acquifer.